allergen
substance that can produce an abnormally vigorous immune response, in which the immune system reacts to fight off a perceived threat that would otherwise be harmless to the body
en-US/ˈælɚˌd͡ʒɛn/
en-GB/ˈæləd͡ʒɛn/
substance that can produce an abnormally vigorous immune response, in which the immune system reacts to fight off a perceived threat that would otherwise be harmless to the body